Transcranial Color Flow Imaging Research Articles

Abstract TP98: Diagnostic Utility Of Transcranial Color Flow Imaging Identifying High Risk Patent Foramen Ovale

Background and Purpose: Recent several studies demonstrated that percutaneous patent foramen ovale (PFO) closure reduced the risk of stroke recurrence for patients with cryptogenic stroke and PFO. Our aim of this retrospective study is to evaluate the usefulness of transcranial color flow imaging (TC-CFI) in the diagnosis of anatomically high risk PFO, in which percutaneous PFO closure is expected to be more effective in preventing embolism. Methods: Subjects were ischemic stroke patients who were investigated the presence of right-to-left shunt (RLS) using TC-CFI and transesophageal echocardiography (TEE). Anatomically high risk PFO evaluated by TEE were defined as satisfying one or more of the following findings: 1) large shunt (more than 20 microbubbles (MB) identified in the left ventricular system), 2) atrial septal aneurism, and 3) the presence of shunt without Valsalva maneuver (VM). TC-CFI was performed in the middle cerebral artery and/or intracranial vertebral artery once without VM and three times with VM, respectively. The number of microembolic signals from MB was determined using international Consensus Criteria (ICC). The accuracy of TC-CFI for high risk PFO diagnosed by TEE was calculated, and then the positive rate of TC-CFI in detecting high risk PFO was also analyzed by TC-CFI’s findings (A: ICC grade II or higher, B: positive without VM, and C: positive on multiple times or in multiple vessels). Results: We analyzed 176 patients (41 females, mean age 64 years) admitted to our facility from July 2019 to July 2021. Of them, 44 patients (25%) had PFO, and 29 patients (16%) were high risk. The diagnostic power of TC-CFI was sufficient, with sensitivity of 93%, specificity of 80%, and accuracy of 89%. The positive rate of each finding was significantly higher in C than in A and B (A: 23%, B: 39%, and C: 55%. P=0.04). Conclusions: To perform the TC-CFI procedure frequently in multiple vessels is useful for screening of high risk PFO.

Query to the Case Report “Microembolic signal detection by transcranial color flow imaging is useful for understanding the morbid state of cancer-related stroke”

Query to the Case Report “Microembolic signal detection by transcranial color flow imaging is useful for understanding the morbid state of cancer-related stroke”

Utility of transcranial color flow imaging for detecting high risk morphology of patent foramen ovale in patients with cerebral infarction

Abstract Background Micro-bubble test by using transcranial color flow imaging (TCCFI) is important as a screening evaluation for diagnosis of paradoxical cerebral embolism which requires the proof of right to left shunt at atrial septum. In addition, high risk features of patent foramen ovale (PFO) that may allow thrombus to easily pass through the PFO itself were previously reported. However, little is known about the association between the degrees on micro-bubble test by TCCFI and the features of high risk PFO. Purpose Our aim is to clarify the relationship between the degree of micro-bubble test in TCCFI and the morphology of PFO from transesophageal echocardiography (TEE). Methods Seventy-seven patients in whom cardiogenic embolism was strongly suspected by neurologists in Showa University from April to December in 2019 were retrospectively studied. 55 patients underwent both TCCFI and TEE with sufficient Valsalva stress. TCCFI grade of micro-bubble test was classified into 3 groups (A: none, B: small, and C: massive), in which signified “none” is no sign of micro-embolic signals (MES) within 30 seconds, “small” is 1 or more MES, and “massive” is so much MES look like a curtain (Figure). Evaluated high risk characteristics of PFO for cerebral embolism as previously reported were as follows; (1) tunnel height, (2) tunnel length, (3) total excursion distance into right and left atrium, (4) existence of Eustachian valve or Chiari network, (6) angle of PFO from inferior vena cava (7) large shunt (20 or more micro-bubbles). Results Of all TCCFI-positive patients (n=32; Group B=19, Group C=13) with cerebral embolism, PFOs were detected in 23 patients in TEE. Therefore, the sensitivity and specificity of TCCFI to PFO were 87% and 63% (AUC=0.75, p<0.001, respectively). Interestingly, all 13 patients (Group C) had manifest PFOs. Moreover, group C include 2 patients with platypnea orthodeoxia syndrome in which hypoxia in the sitting position becomes apparent. Among PFO-positive patients, tunnel height, length, total excursion distance into right and left atrium, and large shunt in TEE were significantly larger in Group C than Group B (p<0.05). Conclusions Micro-bubble test by using TCCFI may have screening advantages in predicting paradoxical cerebral embolism, high-risk morphology of PFO, and platypnea orthodeoxia syndrome. Figure 1 Funding Acknowledgement Type of funding source: None

Ultrasound can detect alternating vertebral artery occlusions due to hangman fracture

AbstractWe present a case of alternating vertebral artery occlusions due to hangman fracture which was detected by repeated ultrasound. An 89‐year‐old woman presented with sudden onset of consciousness disturbance. Magnetic resonance imaging showed bilateral cerebellar ischemic lesions and daily alternating vertebral artery occlusions. Carotid ultrasonography and transcranial color flow imaging showed blood flow changes from day to day which indicated an abnormal hemodynamic status of bilateral vertebral artery. Computed tomography angiography revealed hangman fracture and severe compression of bilateral vertebral artery with thrombi. We applied Halo‐Vest fixation and started the patient on anticoagulation therapy. Then, carotid ultrasonography and transcranial color flow imaging demonstrated improvement of bilateral vertebral artery blood flow. The patient remained free of neurological deficits after Halo‐Vest fixation and anticoagulation. This case highlights the importance of repeated ultrasonographic evaluation of cerebral arteries in patients with ischemic stroke by hangman fracture.

Updated Information for Neuro-anesthesia：The Indication of Transcranial Doppler and Transcranial Color Flow Imaging for Neuro-anesthesia and Intensive Care

Updated Information for Neuro-anesthesia：The Indication of Transcranial Doppler and Transcranial Color Flow Imaging for Neuro-anesthesia and Intensive Care

Microembolic signal detection by transcranial color flow imaging is useful for understanding the morbid state of cancer-related stroke

Microembolic signal detection by transcranial color flow imaging is useful for understanding the morbid state of cancer-related stroke

Usefulness of transcranial color flow imaging: a case report on intracranial stenting

Usefulness of transcranial color flow imaging: a case report on intracranial stenting

Clinical Characteristics of Intracranial Reversed Vertebral Artery Flow Evaluated by Transcranial Color Flow Imaging

Carotid duplex ultrasonography (CUS) has been used to identify reversed vertebral artery flow (RVAF) at the extracranial cervical artery in some patients with subclavian steal syndrome. However, the characteristics of intracranial RVAF as evaluated by transcranial color flow imaging (TC-CFI), which can examine intracranial hemodynamics in a real-time and noninvasive fashion, remain unclear. The goal of this study was to analyze the prevalence of intracranial RVAF and its associated clinical characteristics. Subjects were consecutive patients who underwent TC-CFI and CUS. We evaluated blood flow in both intracranial vertebral arteries (VAs) from the suboccipital echo window using TC-CFI. RVAF was defined as a flow signal directed toward the probe. We calculated the prevalence of intracranial RVAF in our subjects. Then, we investigated vascular condition (ie, site of lesion, stenosis, occlusion, and dissection) using magnetic resonance angiography, computed tomography angiography , and CUS in patients with intracranial RVAF. Seven hundred twenty patients (508 men; median age, 73 years) were included in this study from September 2007 to March 2013. Intracranial RVAF was seen in 12 patients (1.7%; 11 men; median age, 61 years). Among the 12 patients with intracranial RVAF, 8 patients (67%) had ischemia of the vertebrobasilar territory with distal VA occlusion, according to CUS. Of those patients, 6 (75%) had dissection of the VA. TC-CFI detected intracranial RVAF in 1.7% of consecutive examinations in our facility. In vertebrobasilar territory stroke patients with intracranial RVAF, VA dissection may contribute to the development of stroke.

頸部血管超音波で神経症状改善を伴う頭蓋内椎骨動脈の再開通を捉えた1例

An 85-year-old woman came to our hospital due to an inability to live independently from a decline in her activities of daily living. Neurologically, she showed no focal signs, but multiple acute ischemic lesions were evident in the posterior circulation on magnetic resonance imaging. Occlusion of the right intracranial vertebral artery (VA) and stenosis of the left intracranial VA were detected on magnetic resonance angiography (MRA). Carotid duplex ultrasonography (CUS) showed a flow pattern with occlusion of the right VA before the branching of the posterior inferior cerebellar artery. Based upon antegrade flow in the right intracranial VA as evaluated on transcranial color flow imaging, the distal VA territory might have been maintained via collateral flow. With antiplatelet therapy and intravenous injection of argatroban, the patient’s activity gradually improved to the same level as before admission. Recanalization of the right VA was seen on MRA and CUS at 14 days after admission. Reduced cerebellar blood flow due to VA occlusion was thought to be associated with the mechanism affecting her activity levels. Follow-up ultrasonography was useful for evaluating changes in intracranial hemodynamics in this patient who demonstrated neurological improvement.

Transcranial Color Flow Imaging Can Evaluate the Severity of Periventricular Hyperintensity

The goal of this study was to investigate the relationship between white matter lesions on magnetic resonance imaging and flow parameters in the middle cerebral artery (MCA) measured by transcranial color flow imaging. Patients with acute ischemic stroke or transient ischemic attack were included. The relationship between severities of periventricular hyperintensity (PVH) and ultrasonographic parameters in the MCA was investigated. The frequency of PVH was calculated for different categories according to the presence or absence of 2 considerable parameters according to the value of area under the receiver operating characteristic curve. MCA flow was successfully measured in 203 temporal windows among 124 patients. After determining the cutoff value of end-diastolic velocity (EDV) and pulsatility index (PI) for the presence of PVH, 4 different categories were established: Category A, EDV more than 40 cm/second and PI less than .7; Category B, EDV more than 40 cm/second and PI more than .7; Category C, EDV less than 40 cm/second and PI less than .7; and Category D, EDV less than 40 cm/second and PI more than .7. The prevalence of PVH gradually increased along with category (P < .01). The evaluation of MCA parameters using the combination of PI and EDV may be useful for the prediction of PVH.

脳出血の超音波診断

脳出血の超音波診断

Reversible cerebral vasoconstriction syndrome in HELLP syndrome

Introduction: reversible cerebral vasoconstriction syndrome (rcVs) is characterized by severe and hyperacute headaches with or without additional focal neurological deficits, and evidence of vasoconstriction of cerebral arteries which resolves spontaneously within 1–3 months. However, the precise mechanism of rcVs is not fully understood. case report: We report a 33-year-old postpartum woman with rcVs with HELLP syndrome and eclampsia. Magnetic resonance angiography (MrA) of head revealed transient segmental stenosis and dilatation. Especially, most part of the middle cerebral artery (McA) was irregularly thinner at the acute phase than have ever previously reported. transcranial color flow imaging (tccFI) showed the highest peak systolic velocity of middle cerebral artery that has ever reported in rcVs cases (330 cm/s). Histologically, the large areas that showed cytotoxic edema on magnetic resonance imaging at acute phase, which indicated possible infarction at the chronic

Abstract 2959: Diagnosis of Right-to-Left Shunt in Intracranial Vertebral Artery by Transcranial Color Flow Imaging

Objective: Right-to-Left shunt (RLS) detection by Transcranial Doppler is useful for diagnosis of paradoxical embolism. However, we sometimes could not monitor MCA due to insufficient temporal bone window, especially in old patients. Other insonation windows such as transorbital and suboccipital window (basilar artery) are using recently, whereas the ability to detect of intracranial arteries from these windows was not so high. We evaluated usefulness of RLS detection in intracranial vertebral artery (VA) from suboccipital approach that could be measured in almost patients. Methods: We evaluated RLS using transcranial color flow imaging (TC-CFI) in patients with ischemic stroke or transient ischemic attack who could be detected middle cerebral artery (MCA) from temporal bone window and intracranial VA from suboccipital window by TC-CFI. We monitored microembolic signal (MES) at ipsilateral MCA and VA (not hypoplastic side) for 90seconds after injection of 9ml saline agitated with 1ml of air in the right antecubital vein. The procedure was performed three times in each artery with and without Valsalva maneuver. The presence of MES was classified according to Spencer Logarithmic Scale (SLS) criteria. Results: Fifty two patients (46 male, mean age of 64.1±14.3) were included. Twelve patients were positive of MES (23.1%). VA comparison to MCA showed 10 true positive, 40 true negative, 0 false positive and 2 false negative cases (sensitivity 83.3%, specificity 100%, positive predictive value 100%, negative predictive value 95.2% and accuracy 96.2%). In 12 patients with MES, 22 of 36 examinations in MCA were positive of MES (SLS grade I was 20 examinations and grade II was 2 examinations), on the other hand, 20 of 36 examinations in VA were positive (SLS grade I was 20 examinations). The positive ratio of 36 examinations in 12 patients did not show significant difference statistically between MCA and VA. Conclusion: The evaluation of RLS in intracranial VA using TC-CFI from suboccipital window has equal diagnostic ability to MCA, and is useful for the patients with insufficient temporal bone window.

Recanalization of the middle cerebral artery after treatment with tissue plasminogen activator in a patient with embolic occlusion detected by transcranial color-flow imaging.

The patient was a 52-year-old man, who suddenly developed a severe left hemiparesis. Using transcranial color-flow imaging (TC-CFI), we diagnosed him as having an embolic occlusion of the right MCA M1 segment. After treatment with t-PA, recanalization of the MCA M1 segment was demonstrated by TC-CFI. Two hours after t-PA infusion, his neurological signs were normal. We believe that TC-CFI is very useful in the evaluation of MCA M1 segment occlusion after a hyperacute embolic stroke and the effects of treatment with t-PA.

超音波造影剤ＳＨ／ＴＡ‐５０８の臨床第ＩＩＩ相試験 脳血管領域における共同研究の成績

超音波造影剤ＳＨ／ＴＡ‐５０８の臨床第ＩＩＩ相試験 脳血管領域における共同研究の成績

ＳＨ／ＴＡ‐５０８臨床第二相試験 脳血管領域における成績

This phase-two clinical trial was designed to investigate the effectiveness, safety, and usefulness of galactose microparticles (SH/TA-508) as a new ultrasound transpulmonary contrast-enhancing agent for transcranial color flow imaging.Seventy-six patients with clinical indications for transcranial Doppler investigation were entered in this frial. Thirty-eight patients were given an intravenous injection of 8 ml at the concentration of 200 mg/ml, 5 ml at 300 mg/ml, and 4 ml at 400 mg/ml and the other 38 received a two-fold higher volume of the agent at each different concentration. We evaluated the adequacy of signal enhancement and the duration of appropriate signal enhancement on transcranial color-coded flow image after each injection. Safety was determined by clinical and laboratory monitoring for 24 hours.The concentrations of 300 mg/ml and 400 mg/ml were more effective in providing signal enhancement and a long duration of enhancement than 200 mg/ml, and there was no difference in effectiveness between the concentrations of 300 mg/ml and 400 mg/ml. No significant difference in effectiveness was shown between different volumes at the same concentration. Pain at the injection site as an adverse effect was observed in only one patient at injection of 8 ml of 400 mg/ml of the agent.SH/TA-508 was found to be a very useful ultrasound contrast-enhancing agent for transcranial color flow imaging. A suspension of 5 ml of 300 mg/ml seemed to be the optimum volume and concentration for intravenous administration.

Efficacy of Transcranial Color Flow Imaging in Patients with Abnormal Blood Flow Velocity of the Middle Cerebral Artery

PurposeWe used TC-CFI to delineate the abnormal blood flow in the middle cerebral artery (MCA), a segment of which had been found by TCD to be associated with an abnormal blood flow velocity. Our purpose was to find whether or not the procedure is useful in excluding false positive sign.MethodThe subjects were assigned to one of the following two groups: a high velocity group-those who had a maximum systolic flow velocity in the MCA (determined by TCD) that exceeded the mean +2 SD of the normal controls (126 cm/s) ; and a low velocity group-those with a velocity below the mean -2SD (52 cm/s) .In both group, the segmental image of the MCA (where a high or low flow velocity was recorded by TCD) was studied by TC-CFI to elucidate the cause of the flow abnormalities.Results and Conclusion1. The stenotic lesion was easily detected with TC-CFI, because the flow signal changed from red to yellow or a mosaic pattern. The section where the maximum systolic flow velocity (determined after angle correction) exceeded 170 cm/s is indeed stenotic.2. Two explanations are offered for the segment that showed a low flow velocity by TCD: the actual flow velocity was also low; and the existence of a so-called false-positive phenomenon (i.e., the corrected flow velocity is normal because the angle between the MCA and the Doppler beam is large) .3. TC-CFI is very useful in elucidating the relationship between the Doppler beam and the flow through the MCA.

Usefulness of Transcranial Ultrasound Imaging for Intracranial Space Occupied Lesion

We tried to evaluate the usefulness of the transcranial color flow imaging (TCFI) as a noninvasive imaging method for Intracranial space occupied lesion (I-SOL) .METHOD-TCFI (ATL, ULTRAMARK 9® 2.25 MHz phazed arrey, 90° sector scan) was applied from the.. bitemporal “acoustic window” to 22 meningiomas, 12 pituitary adenomas, 5 gliomas, I intraventricular tumor, 4 arteriovenous malformations (AVM), 7 intracerebral hematomas (ICH), 8 chronic subdural hematomas (CSH), 2 acute epidural hematomas (AEH), and 1 pediatric arachnoid cyst. RESULT-We were able to detect 12 meningiomas, 7 adenomas, 1 cystic glioma, 1 ventricular tumor, 2 AVMs, 6 ICHs, 6 CSHs, 2 AEHs, and 1 arachnoid cyst, as clearly defined lesions on B-mode images.It was difficult to visualize the region of the posterior fossa. Frontal and high convexity regions were also difficult to investigate. CONCLUSION-TCFI has great advantages : movability, noninvasiveness and blood flow detection factors. It provides an useful diagnostic method for the I-SOL.

Future Aspect of Transcranial Color Doppler Flow Imaging

Although ultrasonics diagnostic techniques have a great advantage of the nonivasive and realtime application for measuring the viscoelastic properties of the tissue, the accuracy of the brain image has been lower than that of MRI and XCT. The ultrasonic technique, therefore, have been used for only the intraoperative use and biopsy.The recent TCD, however, opened not only the transcranial blood flow measurement, but also the future of the transcranial color flow imaging (TC-CFI) in neurological and neurosurgical fields. Especially, the image of cerebral vasculature given by TC-CFI would have great value in the diagnoses of cerebral vascular diseases (CVD) . From the viewpoint of biomedical engineering, the future aspect of ultrasonic diagnostic application can be summarized by the following three items.(1) Ultrasonics frequency : It is very important to find a suitable ultrasonic frequency and the techniques for improving the ultrasonics refraction and the absorption at the skull It is essential to a maintain high sensitivity for low blood flow velocity.(2) TC-CFI : What cerebral vasculature can be imaged by the TC-CFI? That is, can we capture small branches of main arteries and veins near the Willis circle? The region of capturable vasculature has not yet been clarified by the TC-CFI technique. The improvement of Doppler signal sensitivity would develop the wide area in the brain, which would be an indispensable diagnostic technique.(3) Three dimensional (3D) image of cerebral circulation : TC-CFI has the possibility to reconstruct the 3-D image, which has a great advantage for the noninvasive diagnoses of various CVD such as the aneurysm in curved vessel structure.

Possibility and Limits of Transcranial Color Flow Imaging in Screening the Cerebral Aneurysms

It is generally believed that TCD is not helpful in detecting intracranial aneurysms smaller than 15mm in diameter, to despite great improvement in technology of transcranial Doppler (TCD) in transcranial Doppler angiography (TCDA), three dimentional transcranial Doppler (3D-TCD) and transcranial color flow image (TCFI) . So far there haven't been any reports to challenge this theory. In this study, we examined a 50-yearold female with diffuse subarachnoid hemorrhage. We were able to detect four aneurysms in this patient. The size of aneurysms ranged from 2mm to 9mm in diameter using TCFI under the following criteria before cerebral angiography. We conducted the experiment as follow:1) Set up sample volume from 1.5 × 1.0mm to 3.0 × 1.0mm.2) Carefully scanned the captured artery.3) Detected an appendage structure with pathological blood flow near the normal cerebral artery using axial and coronal view in B-mode scan.4) Detected a pathlogical color-flow image with Doppler sonogram, which indicates a turbulent flow.5) Found normal flow pattern at the proximal and distal portions of the turbulent flow region.This is the first report showing the turbulent flow of small cerebral aneurysms using B-mode scan and Doppler son ogram.We believe that our report indicates the reliability of TCFI for screening unruptured cerebral aneurysms.